Work supporting and rotating mechanism



June 2l, 1938.l A. G. HELDEN I WORK SUPPOMINGV AND RoTATNG MECHANISMFiled oct. 17, 1956 gmc/rm F/LEERT E'. HELDEN SMM/M1 Patented June 21,1938 UNITED STATES PATENT OFFICE WORK SUPPORTING AND' ROTATING 1MECHANISM Application October 17, 1936, Serial No. 106,153

3 Claims.

This invention relates to grinding machines, and more particularly to acrankshaft supporting and rotating mechanism for a double head crankpingrinding machine.

One object of the invention is to provide a thoroughly practicalcrankshaft supporting and clamping mechanism. A further object of theinvention is to provide an improved and simplified spring actuatedcrankshaft clamping mechanism. A further object of the invention is toprovide a yieldable clamping mechanism positively to lock the crankpinin position on a rotary work holder. A further object of the inventionis to provide a yieldable toggle actuated 15v clamping mechanism inwhich the pressure is applied in a direction aligned with the axis ofrotation of the work support. A further object of the invention is toprovide a clamping mechanism in which a yieldable device is provided toclamp a work piece and an adjustment is provided whereby the tension ofsaid yieldable device may be varied as desired. Other objects will be inpart obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one of various possibleembodiments of the mechanical features of this invention,

Fig. 1 is a fragmentary View, partly in section, of the improvedcrankshaft clamping, supporting and rotating mechanism; and

Fig. 2 is a fragmentary sectional view, showing the piping and thecontrol valve for controlling the release Vof the crankshaft clampingmechamsm.

A double head crankshaft grinding machine has been illustrated in thedrawing, comprising a work supporting table I which is adapted to slideon suitable ways on the machine base (not shown) and adapted rotatablyto support a crankshaft II in operative relation with a rotatablegrinding wheel I2 which may be mounted in any old and well known manneron a wheel slide (not shown). The wheel slide is pro- 50 vided with asuitable feed mechanism (not shown) so that the grinding wheel I2 may befed toward and from the crankshaft II to grind the crankpins thereon toa predetermined size. The Work table I 0 is provided with a pair of worksupporting heads I4 and I5 which, as illustrated,

may be formed integral with the table I0 or, if preferred, may be boltedrigidly to the table and provided with a suitable adjustment so that theheads may be moved laterally of the table to align the axis of one headwith the axis of the other.

The heads i4 and I5 are provided with rotatable work supporting spindlesI6 and I1 journaled in the partial bearings I8 and provided withfloating bearing members I9 which may be adjusted relative to the xedportion of the bearings by adjusting screws 20. For further details ofthis bearing construction together with the drive for the spindles,reference may be had to the prior United States patent to C'. H. NortonNo. 1,563,310 dated November 24, 1925.

The work supporting spindles I6 and I1 are provided at their outer endswith sprockets 25 and 26, respectively, which are in turn connected withsprockets 21 and 28 by link chains 29 and 30, respectively. Thesprockets 21 and 28 are mounted on a drive shaft 32 rotatably mounted insuitable bearings 33 and 34 depending from the work table I0. It will beseen from this construction that any rotation of the shaft 32 will betransmitted through the sprockets and chains synchronously to rotate thecrankshaft supporting spindles I6 and I1. The shaft 32 may be driven byany suitable driving mechanism, such as a belt drive from an electricmotor on the machine or from an overhead source of power. This drivecomprises a pulley 35 rotatably mounted on a shaft 36 which is supportedin suitable bearings 31 and 38 in the machine base. A sprocket 39 ismounted on the outer end of the shaft 36 and is connected by a linkchain 40 with a sprocket 4| which is slidably keyed to the shaft 32. Thesprocket 4I is provided with a key 42 so that the sprocket may be heldagainst endwise movement as the table I0 and the shaft 32 are traversedor reciprocated longitudinally but at the same time arranged to permitrotation of the shaft 32 synchronously to rotate the crankshaftsupporting spindles I6 and I1.

It is desirable in a machine of this type to provide a suitablecontrolmechanismfor starting and stopping the rotation of the workspindles. In the preferred construction, a clutch mechanism may beprovided, such as a friction clutch of an old and Well known type. Thisclutch may comprise a cone shaped member 43 which is slidably` keyed tothe shaft 36 and is adapted to engage a correspondingly shaped aperture44 in the pulley 35. A cone shaped sleeve 45 is slidably keyed on theshaft 36 and is adapted to engage the ends of the long arms of aplurality of clutch fingers $6. The clutch ngers I5 are pivotallymounted on a supporting member ll'l and arranged so that their shortarms i8 engage one face of the cone shaped member Q3. It will be readilyapparent from this construction that when the sleeve i5 is moved towardthe right (Fig. l), the fingers l5 are swung about their pivot andoperate to slide the cone shaped member @I3 into engagement with theinternal cone surface ld to lock the pulley 35 to the shaft 36 andthereby start rotation of the crankshaft supporting spindles I6 and I'I.

A yoked member t9 engages an annular groove in the sleeve #l5 so as tocontrol the engaging or disengaging of the clutch. In order that theclutch sleeve Q5 may be readily controlled, a manually operable controllever 5t! is pivotally mounted on a stud 5l so that the lever may beswung in a vertical plane toward and from the machine base. The stud 5lis supported on a pivot 52 so that the lever may be swung in a verticalplane substantially parallel to the ways of the machine. The lever 58 isconnected by -l means of a link 55 to the yoked member 49 which ispivotally mounted on a stud 55 so that any movement of the lever 5Elongitudinally of the machine is transmitted to engage or disengage theclutch. If the lever 59 is thrown toward the Y right into a position50a, as illustrated in dotted lines in Fig. 1, then the clutch sleeve l5is moved toward the right to engage the clutchmember and lock the pulley35 to the shaft 35, thereby transmitting power to they crankshaftsupporting spindles It and Il. If the operator moves the lever 5@ fromposition 59a into full line position 5G, then the sleeve I5 is movedtoward the left and into engagement with a cone shaped aperture 53 whichis fixed on the machine base. The cone shaped sleeve l5 is slidablykeyed to the shaft 36 so that when it comes into engagement with thecone shaped aperture 58, it will serve as a brake to stop the rotationof the crankshaft supporting and rotating spindles.

A clamping mechanism is provided which will rigidly lock the crankshaftII in place for a grinding operation. As illustrated, the inner ends ofthe spindles I5 and Il are provided with en.

larged face plates Sil and 6I to which the work supporting and clampingheads 62 and 53 are secured by means of bolts (ifi. Each of the heads 62and 63 is provided with a fixed partial bearing member S5 adapted tosupport one of the main bearings 66 on the crankshaft Il. The surface ofthe bearing member 65 is arranged to support and align the crankshaft Ilfor grinding. A

lever 68 is pivotally mounted on a stud B9 on each of the work heads 52and 63 and is provided at its outer end with a projecting stud 'l0 whichis threaded within the end of the lever 68 to permit adjustment of thestud relative to the lever. It will be readily apparent from thisconstruction that when the lever S8 is rocked about its pivot 59, thestud l0 is swung into engagement with the peripheral surface of thecrankshaft II and the shaft is held rigidlyin position on bearingm-embers 65.

. In the preferred construction, a toggle Yis provided to swing thelever G8 and to lock. the

L crankshaft I I in rigid engagement with the work This . for example aconstruction such as that shown in the prior United States LettersPatent No. 1,837,342 to H. A. Silven et al. dated December 22, 1931. Thelower end of the lever 'I2 is pivotally mounted on a stud 'i8 secured toa link 'i9 which is in turn pivoted on a stud 89 in the work heads 62and 53. It will be readily apparent from the construction as illustratedin Fig. 1 that as the lever 'l2 is moved in the direction of the arrow,the pivot 8G, being ilxed, will tend to raise the ball and socket jointon the end of the lever 5B and swing the lever 68 about its pivot 69 toswing the clamping stud l0 into engagement with the crankshaft I I tohold the shaft rigidly in position on the heads 62 and 63.

The toggle is preferably operated by a spring actuated mechanism topermit rotation of the work without disturbing the connections andadjustment or operation of the clamping mechanism. As illustrated, rodsand 86 are contained with an aperture within the spindles I6 and Il,respectively. The inner end of each rod 85 and 86 is provided with aprojecting portion 8l supporting a stud S8 which in turn is connected bya yoked member 9U to a short arm 9| of the bell crank lever l2 by a stud92. A screw threaded connection is provided between the yoked member 96and the stud 80 so that the operator may readily adjust the position ofthe stud 92 relative to the operating mechanism.

In order that the crankshaft may be readily unlocked after the grindingoperation has been completed, a fluid pressure operated mechanism isprovided so that the clamping members may be quickly unlocked to permitremoval of the finished crankshaft and replacement thereof with aminimum amount of effort and loss of time. This mechanism comprises apair of cylinders Bl and 98 which are preferably iixedly mounted on theouter ends of the heads I4 and I5 and positioned in axial alignment withthe clamp actuating rods 85 and 86 and the spindles I6 and I'I. Thecylinders 97 and 98 contain slidably mounted pistons 99 and Iil,respectively. The pistons 99 and III@ are connected by anti-frictionbearings Il and I U2 with the outer ends of the clamp actuating rods 85and 86, respectively. The cylinders 91 and 98 and the pistons 99 and IDSare of a relatively large cross sectional area so that sufficientpressure area is provided readily and quickly to actuate the toggleclampsA to release a finish ground crankshaft from the machine.

A fluid pressure system is provided for conveying fluid under pressureto said cylinders. This system may comprise a control valve HB5. Fluidunder pressure may be admitted to the valve H15 from any suitable wellknown fluid pressure source, such as a fluid pump (not shown) within thebase I, through a pipe |06 which enters a valve chamber I Ill, betweenvalve pistons H18 and Ill9 formed integral with a valve stem I I. Thisvalve is preferably of a balanced piston type arranged so that fluidentering the valve chamber IB? equalizes the pressure on each of thepistons |98 and |09 and thereby permits' a ready adjustment of the valvewithout undue exertion onV the part of the operator. When the valve stemis moved outwardly so that the valve pistons |08 and E09 assume thedotted line positions I08a and Ill9a, respectively, the port II2 is openand fluid under pressure is passed through pipe H3 and pipes H4 and II5, into cylinder chambers I l and Ill, respectively, thereby moving thepistons 99 and |00 outwardly (Fig. 2) to operate the toggles and therebyunlock the Work clamps to release a crankshaft after a grindingoperation has been completed. i

A yieldable spring actuated mechanism is provided to actuate theclamping members 68 so as rigidly to lock a crankshaft I I in positionon the work heads 62 and 63. In the preferred form, a massive springunder compression is utilized to move the rods and', respectively,toward each other to actuate the clamping members to lock the shaft inposition. In the preferred construction, a massive compression spring|29 of relatively large diameter, preferably rlarger in diameter thanthe spindle i6, is providedrwithin the cylinder 97 and is interposedbetween the piston 99 and an adjustable end thrust plate I2I. The spring|29 may be of a size as illustrated substantially to fill the cylinder9'I. If necessary, to obtain the desired compression, a spring of largerdiameter may be readily provided by replacing the cylinder 9i with acylinder and piston of larger cross-sectionalarea so that the size ofthe spring may be increased, if desired. Similarly, the length of thecylinder 91 may be of such a dimension as to accommodate a spring of thedesired length to produce a compressional clamping pressurey on the rod85, as required, depending upon the crankshaft to be ground.

The compression of the spring |29 may be adjusted by means of aplurality of adjusting screws |22 and 23 which are screw threadedthrough a cylinder head |29 and are arranged to abut against the thrustplate I2|. By adjusting the screws |22 and |23, the compression of thespring may be readily varied, as desired.

A similar spring pressure clamping mechanism is provided for actuatingthe'rod 86 in the'righthand head (Fig. l) to actuate the clamping jaw von the head 53. This mechanism comprises a spring |25 within thecylinder 99 which is interposed between the piston |99 and an adjustingthrust plate |29. A cylinder head I2'I encloses the outer end of thecylinder 98. A plurality of adjusting screws |28 and |29. ares'crew'threaded, into the cylinder head |2'I and abut against the thrustplate E25. By adjusting the screws |28 and |29, the compression of thespring |25 may be readily increased or decreased, as desired, to producethe desired clamping thrust on the rod 89 to actuate the clampingmechanism and secure the crankshaft II to be ground in engagement withthe supporting head with the desired clamping pressure. It will bereadily appreciated that the clamping springs |29 and |25 serve toproduce a direct end axial movement of the clamping rods 85 and 85, anddue to the fact that the spring is interposed between the piston and theend of the cylinder, serves to produce a clamping pressure by means of amassive nonrotatable spring which bears against the piston whichtransmits a clamping pressure through the piston, the anti-frictionthrust bearing and the rods 85 and 35 to actuate the toggle clamp, asdesired.

It is desirable that vthe work clamping mechanism and the clutchcontrolling the work rotation be so connected or interlocked that therotation of the work head cannot be started until the crankshaft isrigidly held in an operating position in the work heads 62 and 93.Likewise, when grinding has been completed, the rotation of the workheads should be stopped before the clamping jaws 58 may be unlocked. Toaccomplish this, a lever controlling member 39 is provided for the lever59. This member |39 is xed to the base of the machine and is providedwith a substantiallyYL-shaped opening |3| which permits the controllever 59 to be swung in a plane parallel to the work supporting spindlesand also in a plane at right angles to said spindles. The `valve stem II9 is connected to the lever 59 by'means of a block (not shown) which isfixed to the stem II9 and is slidably mounted in a`T-shaped slot (notshown) in the control lever 59, thereby permitting a longitudinalswinging of` the vcontrol lever'as well as a movement axially of thevalve stem I9. lFor a detailed disclosure of thisY construction,reference may be had to the above mentioned prior patent. p

VWhen the lever-59 is in the position illustrated in full lines in Figs.l and 2, the clutch 93 is disengaged, the spindles are stationary andthe clamping mechanism unlocked. When the crankshaft |I is inserted inposition on the partial bearing members 55, the lever 59 is moved intoposition 59a, as shown in dotted lines in Fig. 2, torrnove the valvestem |29 and valve pistons i8 and I9 into a position shown in dottedlines as |9805 and I99a. This movement closes the port H2 and preventsfurther admission of fluid into the cylinder chambers. -When the piston|99 passes by and cuts off the port H2, the released tension of thespring |29v and E25 operating against the fluid in the' cylinders forcesthe fluid from the cylinder chambers H5 and lll and exhausts it throughthe pipes I I4 and H5, through pipe I I3, a chamber within the valve |25and out through a pipe |49, into the reservoir (not shown). As thecompression of the springs |29 and |25 is released by the exhaust offluid, the rods 85 and 89 are moved inwardly' to operate the toggles andthereby swing the clamping jaws 98 so that the studs 'F9 lock thecrankshaft il securely in position. The Yoperator may then swing thecontrol lever 59 from position 59a toward the' right into position 59h(Figs. l and 2). This movement of the control lever 59'slides the clutchsleeve toward the right to throw the clutch member 43 into engagementwith the clutch member M and thereby lock the pulley 35 to the shaft 36and start synchronous rotation of the spindles I6 `and I'I.

Similarly, after the grinding operation is com, pleted, thev operatormoves the control lever 59 from the position 59h (Fig. 2) into position50a, thereby moving the sleeve l5v toward the left to disengage theclutch members i3 and IM and to throw the sleeve 45 into engagement withan aperture wall 58 to brake and stop the rotation of the spindles I6and I1. After the rotation of the spindles has been stopped, theoperator may swing the control lever 59 from the position 59a (Fig. 2)

into position 59, as shown in full lines,` to move the valve stem andvalve pistons from the dotted positions |9811 and |99a into thepositions as shown in full lines |98 and |99. This permits fluidunderpressure to pass through pipe E95, into valve chamber |91, andthrough port l l2, pipe I I3 and pipes I I4 and ||5 into cylinderchambers I I6 and III, respectively. The fluid under pressure in thecylinder chambers I5 and I |'I moves the pistons 99 and |99 away fromeach other, which operates to move the rods 85 and 96 away from each'other against the compression of the springs |29 and |25 to operate thetoggles and unlock the crankshaft after a grinding operation has beencompleted.

The operation of this mechanism will be readily apparent from theforegoing disclosure. A crankshaft II to be ground is placed in positionony the work supporting bearings 65 on the work heads 62 and 63. Thelever 50 is then moved from the full line position (Fig. 1) intoposition a which, as previously described, operates to permit fluid toexhaust through pipes l I4 and I l5 from the cylinder chambers H6 and H1and thereby release the compression of the spring I2i and |25 to causean axial movement of the rods and 86, respectively, which in turnoperates to clamp the crankshaft il rigidly in an operating position onthe work supporting and rotating heads 62 and 63. The lever 50 may thenbe moved from position 56a into position 59h, as shown in Figs. 1 and 2,which starts rotation of the work. The grinding wheel l2 may then be fedtoward the crankpin to be ground to grind and reduce the same to thedesired predetermined size. After the pin has been nish ground, thegrinding wheel I2 is then moved from operative engagement with thecrankpin and the work rotation is stopped by moving the lever 5E? fromposition 5131 into position 50a to disengage the clutch to stop therotation of the work heads 62 and 63, and then into full line positionto unclamp the crankshaft Il after the grinding operation has beencompleted.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense.

1. In a grinding machine, a work head, a hollow rotatable spindlesupported therein, a work supporting member mounted o-n said spindle, aclamping jaw arranged to engage the work piece, a toggle arranged tooperate said jaw, a slidable rod within said spindle, connectionsbetween the rod and toggle to actuate the latter, a cylinder mounted onthe end of said head in axial alignment with said spindle and rod, apiston slidably mounted within said cylinder, an anti-friction bearingwithin said piston and connecting said piston with said rod, means toadmit fluid under pressure to one side of sai-d cylinder to move the rodso as to open said toggle and release said jaw, a compression springWithin said cylinder and interposed between the other side of saidcylinder and a cylinder head, a thrust plate between the cylinder headand the end of said spring, and means to adjust the position of saidplate to increase or decrease the compression of said spring.

2. In a grinding machine, a pair of opposed aligned work heads, arotatable spindle supported in each of said heads, a work supportingmember carried on the inner end of each of said spindles, a clamping jawon each of said heads, a slidably mounted rod within each of saidspindles which is operatively connected to actuate said clamping jaw, acylinder of greater diameter than that of the spindle which is mountedon the end of each head, a piston within each cylinder connected to theouter ends of said rods, a large diameter compression spring within eachof said cylinders and interposed between said pistons and the ends ofsaid cylinder to actuate said rod and clamping jaws to clamp a workpiece in said head, and means to adjust said springs to vary theclamping pressure.

3. In a grinding machine, a pair of opposed aligned work heads, arotatable spindle supported in each of said heads, a work supportingmember carried on the inner end of each of said spindles, a clamping jawon each of said heads, a slidably mounted rod within each of saidspindles which is operatively connected to vactuate said clamping jaw, acylinder of greater diameter than that of the spindle which is mountedon the end of each head, a piston within each cylinder connected to theouter ends of said rods, a large diameter compression spring within eachrends of said springs and cylinders, and means to adjust the position ofsaid plates to adjust the compression of said springs.

ALBERT G. BELDEN.

